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Distribution of Vapor Concentration of Fuel Mixed with High Volatility Component and Low Volatility Component

Doshisha Univ.-Hajime Fujimoto
Published 2010-10-25 by SAE International in United States
The premixed charge compression ignition (PCCI) combustion in a compression ignition (Cl) engine is one of countermeasures against the very much severe regulation for exhaust gas of engine out. The authors have been proposed to use the fuel mixed with high volatility component and low volatility component to actualize PCCI combustion. This kind of fuel injected forms a fine and lean spray by the flash boiling phenomena which depends on the pressure and the temperature. The role of the former fuel is to decrease in the generation of particulate matters (PM) and that of the latter one is to break out the ignition. Thus, it is very much significant to find the distribution of vapor concentration of both fuels in a spray. This paper describes both distributions in a single diesel spray by use of the technique of laser induced fluorescence (LIF) in a constant volume chamber with high temperature at high pressure as the fundamental research.
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Correlation of Spatial-Temporal Ignition and Combustion Processes With Two-Stage Injection Conditions~Fundamental Study in a Rapid Compression and Expansion Machine

Doshisha Univ.-Yoshihito Kido, Masato Kishiura, Jiro Senda, Hajime Fujimoto
Kanazawa Institute of Technology-Yoshimitsu Kobashi
  • Technical Paper
  • 2010-08-0264
Published 2010-05-19 by Society of Automotive Engineers of Japan in Japan
The authors have developed a control technique of mixture distribution, ignition and combustion processes by use of dual-component fuel and/or two-stage injection. It is still necessary to develop an understanding of the effects of the mixture distribution conditions on the spatial-temporal ignition and combustion processes for further advancement. The present study conducts a fundamental experiment in a rapid compression and expansion machine which uses two injectors. The ignition, combustion and emissions characteristics are investigated for injection timings and mass ratio of fuel injected from two injectors by pressure history analysis, optical diagnostic and burnt gas measurement.
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Super High Resolution Photography for Fuel Droplet Distribution Inside Diesel Spray

Chiba Univ.-Tsukasa Hori
Doshisha Univ.-Tetsuya Yano, Hirokazu Adachi, Jiro Senda, Hajime Fujimoto
  • Technical Paper
  • 2009-08-0532
Published 2009-10-07 by Society of Automotive Engineers of Japan in Japan
It is very important things to grasp the spray structure when we evaluate the diesel spray that is unsteady phenomenon. However, it was very difficult to measuring the whole spray structure and particle diameter at the same time. So, we build a lens system with super high spatial resolution and measure these items. As a result, our technique could measure in the high density region of the center of spray and the outer edge of spray. In other words, we could measure the whole area of pilot injection.
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Analysis of Fuel Vapor Distribution in an Evaporative Diesel Spray by Rayleigh Imaging and KIVA-LES

Doshisha Univ.-Hiroshi Tanaka, Tsukasa Hori, Kyosuke Irie, Jiro Senda, Hajime Fujimoto
  • Technical Paper
  • 2008-08-0428
Published 2008-10-22 by Society of Automotive Engineers of Japan in Japan
In this study, validation of KIVA-LES results has been conducted by using experimental equations of spray penetration and Rayleigh scattering method. The penetration of diesel spray simulated by KIVA-LES was evaluated through liquid and vapor length which is estimated by higgen's and dent's equation. The results show that good agreement are obtained in terms of liquid and vapor length between KIVA-LES and experimental equation results. Furthermore, the comparison of radial distribution of mixture fraction between KIVA-LES and Rayleigh imaging results has been conducted. The results show that KIVA-LES results can reproduce experimental results.
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Effects of Fuel Ignitability and Heterogeneity of Fuel Concentration on PCCI Combustion

Doshisha Univ.-Yoshihito Kido, Keisuke Ueda, Yoji Oyama, Jiro Senda, Hajime Fujimoto
Kanazawa Institute of Technology-Yoshimitsu Wada
  • Technical Paper
  • 2008-08-0472
Published 2008-10-22 by Society of Automotive Engineers of Japan in Japan
PCCI combustion simultaneously achieves good fuel economy and very low emissions of NOx and PM. However, since it is a compressed autoignition phenomenon of lean air/fuel mixture, ignition and combustion are predominantly controlled by chemical reactions of fuel. Therefore, this combustion scheme is restricted in partial operation load. To solve those issues using mixture heterogeneity and optimizing fuel ignitability used, authors have developed a control method of mixture heterogeneity. This paper investigates the effects of autoignitability of primary reference fuel and charge heterogeneity on combustion and emissions characteristics by changing the injection quantity ratio of port injection and direct one.
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Visualization of Micro Structure in a Diesel Spray by Use of Photography with High Spatial Resolution

Doshisha University-Hajime Fujimoto, T. Hori, J. Senda, H. Nakagawa, S. Kamata, K. Katsuta
Published 2008-10-06 by SAE International in United States
It is very much necessary for researchers and engineers whose work is the field of combustion in a CI engine to find the information of droplets in a diesel spray. The information is strongly required to construct the model of spray built in the numerical code for its simulation and to be used for the verification of the accuracy of the calculation. This paper describes the photographing system with high spatial resolution, the distribution of droplet size and the vortex scale caused by the droplets motion by means of this system.
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Improvement of Combustion and Emissions in Partially Premixed Charge Compression Ignition Engine Utilizing Flashing Spray of Mixed Fuel

Doshisha Univ.-Yoshimitsu Wada, Jiro Senda, Noriyuki Magara, Keisuke Ueda, Hajime Fujimoto
  • Technical Paper
  • 2008-08-0264
Published 2008-05-21 by Society of Automotive Engineers of Japan in Japan
The authors have applied flashing spray of a mixed fuel into premixed charge compression ignition to achieve low soot and NOx while keeping high thermal efficiency because it allows early fuel injection without suffering from wall-wetting of fuel or poor mixture preparation. In this case, however, the simultaneous ignition of homogeneous mixture causes combustion noise and knocking issue. To control the mixture heterogeneity and to suppress the rapid combustion, multiple fuel injections are employed in this paper. The combustion and emissions characteristics are evaluated for several combinations of secondary injection timings and quantity ratios of each injection event.
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Combustion Method of Diesel Engine Fueled with Hydrogen for High Efficiency

Doshisha Univ.-Takeshi Imuta, Ryuichi Hata, Jiro Senda, Hajime Fujimoto
Mazda Motor Corp.-Taku Tsujimura
  • Technical Paper
  • 2008-08-0284
Published 2008-05-21 by Society of Automotive Engineers of Japan in Japan
A hydrogen-fueled diesel engine was operated with DME added to intake gas because the ignition of hydrogen is enhanced by the chemical reaction of dimethyl ether (DME) during stroke and thus, it has a possibility of achieving high engine performance and stable operations. In this paper, combustion and exhaust emissions characteristics of hydrogen supplied by direct injection were examined by changing the amount of DME or the injection timing of hydrogen. In addition, premixed charge combustion ignition operation was attempted to achieve the combustion with low NOx and high thermal efficiency.
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Effect of Convective Schemes on LES of Fuel Spray by Use of KIVALES

Doshisha University-Tsukasa Hori, Takahiro Kuge, Jiro Senda, Hajime Fujimoto
Published 2008-04-14 by SAE International in United States
In this study, a numerical experiment using a 2D convective equation and LES of an evaporative diesel spray for different convective schemes has been performed to examine effects of convective schemes on a fuel-air mixture formation of the diesel spray simulation and to determine the convective scheme used in KIVALES. In addition to KIVALES original schemes, such as QSOU, PDC and IDC, CIP was incorporated into KIVALES in order to calculate the convective terms with low numerical diffusion. The numerical experiment using the 2D convective equation showed that the numerical diffusion of CIP scheme was lowest in the convective schemes used in present study. However CIP scheme used was not a monotone scheme completely due to the overshoot and the undershoot of the scalar provided near the boundary. Hence, CIP scheme was employed for only the convective term of the LES momentum equation, while the other convective schemes were calculated using QSOU, which is a monotone scheme. The LES spray simulation showed that the sensitivity for convective schemes was significant high in the diesel spray…
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Effect of Operational Condition on PM in Exhausted Gas through CI Engine

Doshisha University-Hajime Fujimoto, J. Senda, T. Yamashita, T. Hori, M. Oshima, H. Tanaka
Published 2007-10-29 by SAE International in United States
The particulate matters (PM) containing in the exhaust gas through a CI engine affects strongly the human health. Thus, it is very significant to measure the mechanism of PM itself generation for actualization of a clean CI engine.On the standpoint mentioned above, the authors carried out the experiments of the characteristics of PM generated from a small high speed DI CI engine with a single cylinder. The variables were the equivalence ratio, the injection timing, the EGR rate and the sort of fuel. As a result, the effect of experimental condition on the distribution of PM is clear through experiments.
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